Centrifugal blower

ABSTRACT

Centrifugal blower ( 1 ) has casing ( 2 ) having scroll ( 6 ) and impeller ( 3 ) incorporated in casing ( 2 ). Casing ( 2 ) has side plate ( 5 ) with suction opening ( 4 ) and motor-fixing side plate ( 8 ) on which motor ( 7 ) is mounted. Impeller ( 3 ) is fixed to motor ( 7 ). Each of side plate ( 5 ) and motor-fixing side plate ( 8 ) has an outer shape of a rectangle with four corners ( 20 ) cut off.

TECHNICAL FIELD

The present invention relates to centrifugal blowers.

BACKGROUND ART

The description below shows a structure of a conventional centrifugalblower incorporated in ventilation blowers, such as a duct fan, and inair conditioners. The centrifugal blower is formed as a self-standingstructure held by a fan casing alone, and is incorporated in an airconditioner and the like. The fan casing has a rectangular side platewith a flange formed on the four sides of the plate. The flange isformed such that each edge of the four sides is bent and raised fromeach side of the side plate. The structure increases the strength of theside plate, allowing the centrifugal blower to be fixed as aself-standing structure. Such structured centrifugal blower is directlyfixed to an air conditioner and the like.

Hereinafter, the structure will be described with reference to FIG. 4showing a perspective view of a conventional centrifugal blower (seePatent literature 1, for example). As shown in FIG. 4, centrifugalblower 101 is formed of casing 102 and impeller 103 built in casing 102.Casing 102 is formed of side plate 105 having suction opening 104,scroll 106, and motor-fixing side plate 108 on which motor 107 ismounted. Impeller 103 is fixed to motor 107.

When motor 107 drives impeller 103 to rotate, suction air 109 flowsthrough suction opening 104 into casing 102 via impeller 103. The airthen blows out of impeller 103 and is pressurized in casing 102. Havingbeen converted from dynamic pressure to static pressure, the air flowsout of discharge opening 110 as discharge air 111.

Centrifugal blower 101 is designed as a self-standing structure held bycasing 102 alone. For the purpose above, each of side plate 105 andmotor-fixing side plate 108 is formed into a rectangle with flange 112disposed on its four sides. Flange 112 works as a reinforcement rib,which protects side plate 105 and motor-fixing side plate 108 from awarp or deformation in the direction of the plate surfaces and enhancesthe strength of them. With the structure above, centrifugal blower 101can be used as a self-standing structure held by casing 102 alone. Suchstructured centrifugal blower 101 is directly fixed to an airconditioner and the like.

CITATION LIST Patent Literature

PTL 1: Japanese Unexamined Utility Model Application Publication No.62-133998

SUMMARY OF THE INVENTION

FIG. 5 is a top view of a conventional centrifugal blower in a packedstate, i.e., shows centrifugal blower 101 in a packed state seen fromabove. According to centrifugal blower 101, as shown in FIG. 4 and FIG.5, the own weight of motor 107 is commonly supported by motor-fixingside plate 108. In packing, suction opening 104 of the centrifugalblower is faced to bottom 114 of container box 113 so that the motor'sown weight applied to motor-fixing side plate 108 is supported by theentire structure of casing 102.

Centrifugal blower 101 has a shape of a cuboid or cube having corners115. If blower 101 packaged in the box is accidentally dropped, corners115 can be damaged by the impact of the drop. To protect corners 115from the drop impact, buffering area 116 has to be formed betweencontainer box 113 and the body of centrifugal blower 101. The need forbuffering area 116 has brought a problem—increase in packaging volume.

The centrifugal blower of the present invention contains a casing havinga scroll and an impeller incorporated in the casing. The casing has aside plate with a suction opening and a motor-fixing side plate on whichthe motor is mounted. The impeller is fixed to the motor. Each of theside plate and the motor-fixing side plate has an outer shape of arectangle with the four corners cut off.

When such formed centrifugal blower is packed in a container box whosebottom has a size approximately the same as the external dimensions ofthe centrifugal blower, a space is kept between a cut-off part and thecontainer box. That is, the structure eliminates the corners that areeasily damaged if the centrifugal blower packaged in the box isaccidentally dropped. By virtue of the structure with no need ofbuffering material at the corners in packing, the package volume willnot increase.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a centrifugal blower of an exemplaryembodiment of the present invention.

FIG. 2 is a sheet-metal development view of a motor-fixing side plate ofthe centrifugal blower.

FIG. 3 is a top view of the centrifugal blower in a packed state.

FIG. 4 is a perspective view of a conventional centrifugal blower.

FIG. 5 is a top view of the centrifugal blower in a packed state.

DESCRIPTION OF EMBODIMENT

Hereinafter, an exemplary embodiment of the present invention will bedescribed with reference to the accompanying drawings.

Exemplary Embodiment

FIG. 1 is a perspective view of a centrifugal blower of the exemplaryembodiment of the present invention. As shown in FIG. 1, centrifugalblower 1 has casing 2 and impeller 3 built in casing 2. Casing 2 hasside plate 5 having suction opening 4, scroll 6, and motor-fixing sideplate 8 on which motor 7 is mounted.

Impeller 3 is fixed to the rotation shaft of motor 7. The rotation ofimpeller 3 driven by motor 7 allows suction air 9 to flow into casing 2from suction opening 4 via impeller 3. The air then blows out ofimpeller 3 and is pressurized in casing 2. Having conversion fromdynamic pressure to static pressure, the air flows out of dischargeopening 10 as discharge air 11.

Each of side plate 5 and motor-fixing side plate 8 has an outer shape,as an anterior view facing suction opening 4, of a rectangular whosefour corners 20 cut off. Side plate 5 and motor-fixing side plate 8should preferably be disposed such that long sides 12 and short sides 13of side plate 5 are parallel to those of motor-fixing side plate 8.Further preferably, long sides 12 and short sides 13 of side plate 5should be the same as long sides 12 and short sides 13, respectively, ofmotor-fixing side plate 8. Side plate 5 and motor-fixing side plate 8have an outer shape of octagon. Besides, each of side plate 5 andmotor-fixing side plate 8 has flange 14 standing upright like a wall onthe periphery of the plate.

FIG. 2 is a sheet-metal development view of the motor-fixing side plateof the centrifugal blower; specifically, it is a sheet-metal developmentview of motor-fixing side plate 8 with flange 14 not yet formed. Bendsection 15 of FIG. 2 is a line connecting between adjacent edges 20 a offour corners 20 of motor-fixing side plate 8. Similarly, bend section 15of side plate 5 shown in FIG. 1 is a line connecting between adjacentedges 20 a of four corners 20. Flange 14 is formed parallel to bendsection 15 in a manner that each side of the plates is outwardly bent atbend section 15.

Bend section 15 is formed on each long side 12. Bend section 15 hasextended sections 16 extended along each long side 12 on the side ofshort side 13. That is, flange 14 has extended sections 16 extended fromthe both ends of bend section 15. Flange 14 at short side 13 is soformed that each of extended sections 16 is bent at bend line 15 a andthen adjacent two extended sections 16 are overlapped with each other.Flange 14 on short side 13 shown in FIG. 1 is thus completed. Fourcorners 20 are cut off in the same shape, which allows flange 14 to beeasily formed.

The workings and effect of the aforementioned structure will bedescribed below. FIG. 3 is a top view of the centrifugal blower in apacked state of the exemplary embodiment. Specifically, FIG. 3 showscontainer box 18, seen from above, in which centrifugal blower 1 ispacked. Centrifugal blower 1 is packed in container box 18 in a mannerthat motor-fixing side plate 8 places above. Container box 18 has bottom17 that is approximately the same as the outside dimension of side plate5 of centrifugal blower 1 shown in FIG. 1; specifically, bottom 17 is alittle bit larger than the rectangle formed by long sides 12 of sideplate 5.

When centrifugal blower 1 is packed in the box, space 19 is retainedbetween container box 18 and the cut-off of side plate 5 andmotor-fixing side plate 8. When a device in a packed state is droppeddown, the most vulnerable part is an angulated section of the device. Asshown in FIG. 3, centrifugal blower 1 has no angulated section and space19 is formed instead. Space 19 is a buffer against an accidental drop ofcentrifugal blower 1 in a packed state, working as impact absorption.Container box 18 absorbs the drop impact while deforming, protectingcentrifugal blower 1 from damage.

As shown in FIG. 1, long sides 12 of side plate 5 and motor-fixing sideplate 8 should preferably be the same in size and be disposed inparallel; similarly, short sides 13 of the two plates should preferablybe the same in size and be disposed in parallel. Further preferably, thefour sides of container box 18 of FIG. 3 in which centrifugal blower 1is packed should be the same in size. The structure eliminateslimitation on packing positioning centrifugal blower 1 (i.e., eliminateswrong orientation of centrifugal blower 1 in packing), making space 19for sure.

Although side plate 5 and motor-fixing side plate 8 of the embodiment inFIG. 1 have an outer shape of octagon, the octagonal shape may haverounded-off corners. That is, side plate 5 and motor-fixing side plate 8may be substantially shaped into an octagon with the corners roundedoff. The structure—even when side plate 5 and motor-fixing side plate 8are substantially shaped into an octagon—protects centrifugal blower 1in a packed state from drop impact.

In the embodiment, each of side plate 5 and motor-fixing side plate 8shown in FIG. 1 has eight sides of two pairs of long sides 12 facingeach other and two pairs of short sides 13 facing each other, but it isnot limited to; each plate may contain more sides, as long as having atleast eight.

In the embodiment, flange 14 at each short side 13 of side plate 5 andmotor-fixing side plate 8 shown in FIG. 1 is formed such that adjacenttwo extended sections 16 are overlapped with each other, but it is notlimited to; short side 13 may contain a flange part connected to flange14 on long side 12. In that case, the flange part is bent together withflange 14 so as to form flange 14 on short side 13.

According to the structure of the embodiment, flange 14 shown in FIG. 1is easily formed by bending without an additional component. Further,flange 14 works as a reinforcement rib, which protects side plate 5 andmotor-fixing side plate 8 from a warp or deformation in the direction ofthe plate surfaces.

Flange 14 shown in FIG. 2 is formed of extended sections 16 overlappedwith each other. When the side plate is carried on and suspended forfixing while flange 14 is being held, the direction in which the forceis exerted agrees with the connecting direction of adjacent flange 14.This increases the strength of flange 14.

The structure increases the strength of side plate 5 and motor-fixingside plate 8 shown in FIG. 1, allowing centrifugal blower 1 to be fixedas a self-standing structure by casing 2 alone. Such structuredcentrifugal blower 1 is directly amounted on air conditioners and thelike. Besides, the structure eliminates the need of buffer material forprotecting corners when centrifugal blower 1 is packed, reducing thepackage volume of the product.

INDUSTRIAL APPLICABILITY

The present invention is applicable not only to centrifugal blowers butalso to packing of various devices.

REFERENCE MARKS IN THE DRAWINGS

1 centrifugal blower

2 casing

3 impeller

4 suction opening

5 side plate

6 scroll

7 motor

8 motor-fixing side plate

9 suction air

10 discharge opening

11 discharge air

12 long side

13 short side

14 flange

15 bend section

15 a bend line

16 extended section

17 bottom

18 container box

19 space

20 four corners

20 a edge

1. A centrifugal blower comprising: a casing having a scroll, a sideplate having a suction opening, and a motor-fixing side plate on which amotor is mounted; and an impeller incorporated in the casing, whereinthe impeller is fixed to the motor, and each of the side plate and themotor-fixing side plate has an outer shape of a rectangle with fourcorners cut off.
 2. The centrifugal blower of claim 1, wherein each ofthe side plate and the motor-fixing side plate has a flange standingupright like a wall on a periphery of the plate.
 3. The centrifugalblower of claim 2, wherein each of the side plate and the motor-fixingside plate has a bend section that is a line connecting adjacent edgesof the four corners, and the flange is formed parallel to the bendsection in a manner that the plates is bent outwardly at the bendsection.
 4. The centrifugal blower of claim 3, wherein the flange hasextended sections extended from both ends of the bend section, and theextended sections are overlapped with each other to form the flange. 5.The centrifugal blower of claim 4, wherein the four corners are cut offin an identical shape.
 6. The centrifugal blower of claim 1, whereineach of the side plate and the motor-fixing side plate has an octagonalouter shape.